Methods and systems for vacuum powder placement in additive manufacturing systems

ABSTRACT

A method for fabricating a component of with an additive manufacturing system include entraining a first portion of first material particles in an airflow generated by a vacuum source and engaging the first portion of the first material particles against an air permeable screen. The first portion of the first material particles is deposited onto a build platform. The method also includes entraining a second portion of second material particles in the airflow and engaging the second portion of the second material particles against the air permeable screen. The second portion of the second material particles is deposited onto the build platform. An energy source transfers heat to at least a portion of at least one of the first portion of the first material particles or the second portion of the second material particles to facilitate consolidating material particles to fabricate the component.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. provisional patent applicationSer. No. 62/441,640, filed Jan. 3, 2017, which is hereby incorporated byreference in its entirety.

BACKGROUND

The subject matter disclosed herein relates generally to additivemanufacturing systems and, more particularly, to additive manufacturingsystems including a material delivery system for depositing materialparticles onto a build platform.

At least some additive manufacturing systems involve the consolidationof a powdered material to fabricate a component. Such systems producegeometrically complex components from powdered materials at a reducedcost and with improved manufacturing efficiency as compared totraditional manufacturing techniques. Some known additive manufacturingsystems, such as Direct Metal Laser Melting (DMLM), Direct Metal LaserSintering (DMLS), Selective Laser Sintering (SLS), Selective LaserMelting (SLM), and Electron Beam Melting (EBM) systems, fabricatecomponents using a beam from an energy source and a powdered material,such as a powdered metal. In such additive manufacturing systems, theproperties of the component are at least partially determined by theproperties of the material used to form the component. In someinstances, it is desirable to fabricate components that have variationsand localized material properties. Accordingly, at least some componentsare formed from two or more separate components with differentproperties joined together. However, the joined components may have anincreased cost of assembly and/or may have an increased risk of failurein comparison to a single component, due in part to the joint betweenthe components.

BRIEF DESCRIPTION

In one aspect, a method of fabricating a component using an additivemanufacturing system is provided. The method includes entraining a firstportion of first material particles in an airflow generated by a vacuumsource and engaging the first portion of the first material particlesagainst an air permeable screen. In addition, the method includesdepositing the first portion of the first material particles onto abuild platform. The method also includes entraining a second portion ofsecond material particles in the airflow and engaging the second portionof the second material particles against the air permeable screen.Furthermore, the method includes depositing the second portion of thesecond material particles onto the build platform. The method includestransferring heat to at least a portion of at least one of the firstportion of the first material particles or the second portion of thesecond material particles with an energy source to facilitateconsolidating the first portion of the first material particles and thesecond portion of the second material particles to fabricate thecomponent.

In another aspect, an additive manufacturing system for fabricating acomponent is provided. The additive manufacturing system includes anenergy source, a build platform configured to hold a plurality of firstmaterial particles and a plurality of second material particles, and amaterial delivery system. The material delivery system includes adispenser assembly comprising a plurality of vacuum valves and an airpermeable screen, and a vacuum source coupled in fluid communication tosaid plurality of vacuum valves. The additive manufacturing system alsoincludes a controller configured to open a first subset of vacuum valvesof the plurality of vacuum valves to generate an airflow through thefirst subset of vacuum valves and the air permeable screen to retrievethe plurality of first material particles. The controller is furtherconfigured to open a second subset of vacuum valves of the plurality ofvacuum valves to generate an airflow through the second subset of vacuumvalves and the air permeable screen to retrieve the plurality of secondmaterial particles. Moreover, the controller is configured to depositthe plurality of first material particles and the plurality of secondmaterial particles onto the build platform, and actuate the energysource to transfer heat to at least one of the plurality of firstmaterial particles and the plurality of second material particles basedon a build parameter to facilitate consolidating the plurality of firstmaterial particles and the plurality of second material particles tofabricate said component.

In yet another aspect, a material delivery system for an additivemanufacturing system is provided. The material delivery system includesa dispenser assembly comprising a plurality of vacuum valves and an airpermeable screen. The material delivery system also includes a vacuumsource coupled in fluid communication to the plurality of vacuum valves.Moreover, the material delivery system includes a mounting systemcoupled to the dispenser assembly.

DRAWINGS

These and other features, aspects, and advantages of the presentdisclosure will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a schematic view of an exemplary additive manufacturingsystem;

FIG. 2 is a schematic view of a portion of the additive manufacturingsystem shown in FIG. 1 including a material delivery system;

FIG. 3 is a schematic plan view of a portion of the additivemanufacturing system shown in FIG. 1 including the material deliverysystem shown in FIG. 2;

FIG. 4 is a schematic diagram of an array arrangement of individuallycontrollable vacuum valves for use with a dispenser assembly of thematerial delivery system shown in FIG. 2;

FIG. 5 is a block diagram of a controller for use with additivemanufacturing system shown in FIG. 1; and

FIG. 6 is a flow chart of a method that may be implemented to fabricatea component using the additive manufacturing system shown in FIG. 1.

Unless otherwise indicated, the drawings provided herein are meant toillustrate features of embodiments of the disclosure. These features arebelieved to be applicable in a wide variety of systems comprising one ormore embodiments of the disclosure. As such, the drawings are not meantto include all conventional features known by those of ordinary skill inthe art to be required for the practice of the embodiments disclosedherein.

DETAILED DESCRIPTION

In the following specification and the claims, reference will be made toa number of terms, which shall be defined to have the followingmeanings.

The singular forms “a”, “an”, and “the” include plural references unlessthe context clearly dictates otherwise.

“Optional” or “optionally” means that the subsequently described eventor circumstance may or may not occur, and that the description includesinstances where the event occurs and instances where it does not.

Approximating language, as used herein throughout the specification andclaims, may be applied to modify any quantitative representation thatcould permissibly vary without resulting in a change in the basicfunction to which it is related. Accordingly, a value modified by a termor terms, such as “about”, “approximately”, and “substantially”, are notto be limited to the precise value specified. In at least someinstances, the approximating language may correspond to the precision ofan instrument for measuring the value. Here and throughout thespecification and claims, range limitations may be combined and/orinterchanged; such ranges are identified and include all the sub-rangescontained therein unless context or language indicates otherwise.

As used herein, the terms “processor” and “computer,” and related terms,e.g., “processing device,” “computing device,” and “controller” are notlimited to just those integrated circuits referred to in the art as acomputer, but broadly refers to a microcontroller, a microcomputer, afield programmable gate array (FPGA), a programmable logic controller(PLC), and application specific integrated circuit, and otherprogrammable circuits, and these terms are used interchangeably herein.In the embodiments described herein, memory may include, but it notlimited to, a computer-readable medium, such as a random access memory(RAM), a computer-readable non-volatile medium, such as a flash memory.Alternatively, a floppy disk, a compact disc-read only memory (CD-ROM),a magneto-optical disk (MOD), and/or a digital versatile disc (DVD) mayalso be used. In addition, in the embodiments described herein,additional input channels may be, but are not limited to, computerperipherals associated with an operator interface such as a mouse and akeyboard. Alternatively, other computer peripherals may also be usedthat may include, for example, but not be limited to, a scanner.Furthermore, in the exemplary embodiment, additional output channels mayinclude, but not be limited to, an operator interface monitor.

Further, as used herein, the terms “software” and “firmware” areinterchangeable, and include any computer program storage in memory forexecution by personal computers, workstations, clients, and servers.

As used herein, the term “non-transitory computer-readable media” isintended to be representative of any tangible computer-based deviceimplemented in any method of technology for short-term and long-termstorage of information, such as, computer-readable instructions, datastructures, program modules and sub-modules, or other data in anydevice. Therefore, the methods described herein may be encoded asexecutable instructions embodied in a tangible, non-transitory,computer-readable medium, including, without limitation, a storagedevice and/or a memory device. Such instructions, when executed by aprocessor, cause the processor to perform at least a portion of themethods described herein. Moreover, as used herein, the term“non-transitory computer-readable media” includes all tangible,computer-readable media, including, without limitation, non-transitorycomputer storage devices, including without limitation, volatile andnon-volatile media, and removable and non-removable media such asfirmware, physical and virtual storage, CD-ROMS, DVDs, and any otherdigital source such as a network or the Internet, as well as yet to bedeveloped digital means, with the sole exception being transitory,propagating signal.

Furthermore, as used herein, the term “real-time” refers to at least oneof the time of occurrence of the associated events, the time ofmeasurement and collection of predetermined data, the time to processthe data, and the time of a system response to the events and theenvironment. In the embodiments described herein, these activities andevents occur substantially instantaneously.

The systems and methods described herein relate to additivemanufacturing systems, such as Direct Metal Laser Melting (DMLM)systems. The embodiments described herein include an energy source foremitting a focused energy beam and a material delivery system. Thematerial delivery system retrieves a plurality of particles of a firstmaterial and deposits or places the particles on a build platform. Inaddition, the material delivery system retrieves a plurality ofparticles of a second material, different from the first material, anddeposits the particles on the build platform, such that the particles ofthe first and second material define a layer of a component. Thematerial delivery system includes a vacuum source coupled to a pluralityof valves to apply a suction force to retrieve and deposit the particlesof material. In one embodiment, the material delivery system retrievesand deposits particles of a sacrificial material, i.e., a material thatis not part of the component, to provide support to the component duringfabrication. Accordingly, the described embodiments facilitate providingthe component with distinct, localized material properties.

FIG. 1 is a schematic view of an exemplary additive manufacturing system10. In the exemplary embodiment, additive manufacturing system 10 is adirect metal laser melting (DMLM) system. While additive manufacturingsystem 10 is described herein as a DMLM system, it is noted thatadditive manufacturing system 10 can be any powder bed fusion processthat enables additive manufacturing system 10 to fabricate a componentusing a focused energy device and at least one powdered material. Forexample, and without limitation, additive manufacturing system 10 can bea Direct Metal Laser Sintering (DMLS) system, a Selective LaserSintering (SLS) system, a Selective Laser Melting (SLM) system, and anElectron Beam Melting (EBM) system.

Additive manufacturing system 10 includes an energy source 12 opticallycoupled to optics 14 and galvanometers 16 for controlling the scanningof energy source 12. In the exemplary embodiment, energy source 12 is alaser device, such as a neodymium-doped yttrium aluminum garnet (Nd:YAG)solid-state laser, that emits energy beam 20. In alternativeembodiments, additive manufacturing system 10 includes any energy source12 that enables additive manufacturing system 10 to function asdescribed herein, such as one of a continuous, a modulated, a pulsedwave laser, or an electron beam generator. In addition, in someembodiments, additive manufacturing system 10 includes a diode fiberlaser array that includes a plurality of diode lasers coupled to aplurality of optical fibers. In such embodiments, the diode fiber arraysimultaneously directs multiple laser beams from the optical fiberstowards a surface or build platform to heat at least one powderedmaterial. Alternatively or in addition, additive manufacturing system 10may include more than one energy source. For example, withoutlimitation, an alternative additive manufacturing system may have afirst energy source having a first power output and a second energysource having a second power output different from the first poweroutput, or an alternative additive manufacturing system may have atleast two energy sources having substantially the same power output.However, additive manufacturing system 10 may include any combination ofenergy sources that permit additive manufacturing system 10 to functionas described herein.

In the exemplary embodiment, additive manufacturing system 10 alsoincludes a computer control system, or controller 18. Galvanometers 16are controlled by controller 18 and deflect a beam 20 of energy source12 along a predetermined path to form a melt pool. In one embodiment,the predetermined path is on a surface or build platform 22. In otherembodiments, galvanometers 16 are deflect beam 20 along a predeterminedpath to facilitate sintering, or otherwise consolidating particles ofmaterial. Sintering is a term used to refer to producingthree-dimensional (3D) components by using, for example, a laser beam tosinter or melt a powder material. More accurately, sintering entailsfusing (agglomerating) particles of a powder material at a temperaturebelow the melting point of the powder material, whereas melting entailsfully melting particles of a powder material to form a solid mass. Thephysical processes associated with laser sintering or laser meltinginclude heat transfer to a powder material and then either sintering ormelting the powder material.

In the exemplary embodiment, galvanometers 16 included a mirror 62operatively coupled to an actuator 64. Actuator 64 moves (specifically,rotates) mirror 62 in response to signals received from controller 18,and thereby deflect beam 20 towards and across selective portions ofbuild platform 22. In some embodiments, mirror 62 includes a reflectivecoating that has a reflectance spectrum that corresponds to thewavelength of beam 20. In alternative embodiments, additivemanufacturing system 10 includes any scanning device that enablesadditive manufacturing system 10 to function as described herein. Forexample, in some embodiments, galvanometers 16 includes two mirrors 62and two actuators 64, each operatively coupled to one of mirrors 62. Inother embodiments, galvanometers 16 includes, for example, and withoutlimitation, two-dimension (2D) scan galvanometers, three-dimension (3D)scan galvanometers, dynamic focusing galvanometers, and/or any othergalvanometer system used to deflect beam 20 of energy source 12.Additive manufacturing system 10 also includes a material deliverysystem 24 that delivers particles of material to build platform 22.

In the exemplary embodiment, build platform 22 supports at least aplurality of first material particles 26 and a plurality of secondmaterial particles 28 delivered by material delivery system 24. Firstmaterial particles 26 and second material particles 28 are powderedbuild materials that are consolidated, i.e., heated and/or melted, andcooled and/or re-solidified, during the additive manufacturing processto fabricate a component 30. In particular, energy source 12 transfersheat to first material particles 26 and second material particles 28,e.g., generates a melt pool or sinters the materials, to facilitateconsolidating the materials in component 30. In the exemplaryembodiment, first material particles 26 and second material particles 28include, for example, and without limitation, a gas-atomized alloy ofone or more of cobalt, iron, aluminum, titanium, nickel, steel, andvarious combinations thereof. Alternatively, first material particles 26and second material particles 28 include any material type that enablesadditive manufacturing system 10 to function as described herein, suchas, for example, and without limitation, ceramic powders, metal powdersmade via non-gas atomization routes, metal-coated ceramic powders,thermoset resins, and thermoplastic resins. While described herein asutilizing first material particles 26 and second material particles 28to fabricate component 30, it is noted that any number of materials maybe used to fabricate a component, such as component 30.

In the exemplary embodiment, additive manufacturing system 10 isoperated to fabricate component 30 by a layer-by-layer manufacturingprocess. Component 30 is fabricated from an electronic representation ofthe 3D geometry of component 30. The electronic representation may beproduced in a computer aided design (CAD) or similar file. The CAD fileof component 30 is converted into a layer-by-layer format that includesa plurality of build parameters 31 for each layer. In the exemplaryembodiment, component 30 is arranged electronically in a desiredorientation relative to the origin of the coordinate system used inadditive manufacturing system 10. The geometry of component 30 is slicedinto a stack of layers of a desired thickness, such that the geometry ofeach layer is an outline of the cross-section through component 30 atthat particular layer location. A “toolpath” or “toolpaths” aregenerated across the geometry of a respective layer. Build parameters 31are applied along the toolpath or toolpaths to fabricate that layer ofcomponent 30 from the material used to construct component 30. The stepsare repeated for each respective layer of component 30 geometry. Oncethe process is completed, an electronic computer build file (or files)is generated including all of the layers. The build file is loaded intocontroller 18 of additive manufacturing system 10 to control the systemduring fabrication of each layer.

After the build file is loaded into controller 18, additivemanufacturing system 10 is operated to generate component 30 byimplementing the layer-by-layer manufacturing process, such as a directmetal laser melting method. The exemplary layer-by-layer additivemanufacturing process does not use a pre-existing article as theprecursor to the final component, rather the process produces component30 from a raw material in a configurable form, such as a plurality ofparticles or a powder. For example, without limitation, a steelcomponent can be additively manufactured using a steel powder. Additivemanufacturing system 10 enables fabrication of components using a broadrange of materials, for example, without limitation, metals, ceramics,and polymers.

FIG. 2 is a schematic view of a portion of additive manufacturing system10 including material delivery system 24. FIG. 3 is a schematic planview of a portion of additive manufacturing system 10 including materialdelivery system 24. In the exemplary embodiment, material deliverysystem 24 includes a vacuum source 32 coupled to a dispenser assembly34, and a mounting system 50 coupled to dispenser assembly 34. Mountingsystem 50 is coupled in communication with controller 18, whichtranslates or moves mounting system 50 in the X, Y, and Z axes,indicated generally at 52, to facilitate retrieving and depositing atleast first material particles 26 and second material particles 28 forfabricating a layer of component 30 (shown in FIG. 1). Dispenserassembly 34 includes a vacuum manifold 36 and a plurality ofindividually controllable vacuum valves 38, arranged in an array,coupled to vacuum manifold 36. Dispenser assembly 34 also includes a gasor air permeable screen 40 (or membrane) coupled to the plurality ofvacuum valves 38, opposite vacuum manifold 36. Screen 40 has a pluralityof pores or openings sized to allow air to pass through screen 40, whilesubstantially preventing first material particles 26 and second materialparticles 28 from passing through screen 40.

In the exemplary embodiment, material delivery system 24 also includesat least a first material supply source 54 and a second material supplysource 56. Alternatively, material delivery system 24 includes anynumber of material sources required to build component 30. In theexemplary embodiment, first material supply source 54 and secondmaterial supply source 56 hold a quantity of first material particles 26and second material particles 28, respectively. Dispenser assembly 34retrieves portions of at least first material particles 26 and secondmaterial particles 28 from first material supply source 54 and secondmaterial supply source 56, respectively, and deposits the materials ontobuild platform 22. With reference to FIG. 3, as described herein,dispenser assembly 34 translates or moves relative to build platform 22.In particular, dispenser assembly 34 translates or moves laterally(i.e., in the X-Y plane) relative to build platform 22. In addition,dispenser assembly 34 translates or moves towards and away from buildplatform 22 (i.e., in the Z direction). As such, material deliverysystem 24 retrieves and deposits at least one of first materialparticles 26 and second material particles 28 in any desired pattern onbuild platform 22. In alternative embodiments, material delivery system24 translates or moves in any manner that enables additive manufacturingsystem 10 to function as described herein.

In the exemplary embodiment, first material particles 26 and secondmaterial particles 28 are substantially level. In addition, secondmaterial particles 28 are deposited with substantially the samethickness as first material particles 26. Accordingly, screeding orleveling of first material particles 26 and second material particles 28is not required. Omitting the screeding process of first materialparticles 26 and/or second material particles 28 facilitates reducingmixing of first material particles 26 and second material particles 28that occurs during screeding. Alternatively, in some embodiments, firstmaterial particles 26 and/or second material particles 28 are screededor leveled. For example, in some embodiments, first material particles26 are screeded prior to deposition of second material particles 28. Inother embodiments, first material particles 26 is at least partiallyfixed in position on build platform 22 to facilitate screeding of secondmaterial particles 28.

As shown in FIGS. 2 and 3, material delivery system 24 optionallyincludes a sacrificial material supply source 58 containing a quantityof sacrificial material particles 60. Dispenser assembly 34 retrievesportions of sacrificial material particles 60 from first sacrificialmaterial supply source 58 and deposits sacrificial material particles 60onto build platform 22. In particular, sacrificial material particles 60are deposited in areas defined between first material particles 26 andsecond material particles 28 to function as a support material forcomponent 30 during fabrication. In one embodiment, sacrificial materialparticles 60 are formed from a magnetic material and first materialparticles 26 and second material particles 28 are formed fromnon-magnetic materials. As such, after fabrication of component 30, amagnetic force is used to facilitate removing sacrificial materialparticles 60. In addition, in some embodiment, sacrificial materialparticles 60 are formed from a ceramic material and first materialparticles 26 and second material particles 28 are formed from metalmaterials. As such, sacrificial material particles 60 are notconsolidated with first material particles 26 and second materialparticles 28 during fabrication of component 30.

FIG. 4 is a schematic diagram of an array arrangement 100 ofindividually controllable vacuum valves 38 for use with dispenserassembly 34 (shown in FIG. 3). In the exemplary embodiment, theplurality of vacuum valves 38 are arranged in M×N array arrangement 100,where M represent a number of columns of vacuum valves 38 and Nrepresents a number of rows of vacuum valves 38. In the exemplaryembodiment, array arrangement 100 includes six rows N and eight columnsM. Alternatively, array arrangement 100 includes any number of columnsand rows of vacuum valves 38 that enable additive manufacturing system10 to function as described herein. For example, and without limitation,in one embodiment, array arrangement 100 of the plurality of vacuumvalves 38 is arranged in a size and a shape to substantially correspondto a size and a shape of build platform 22. In the exemplary embodiment,rows N are arranged such that each succeeding row is aligned with theprevious row, as indicated by centerlines 102 and 104. Alternatively,rows N are arranged in any desirable alignment with a succeeding rowthat enables additive manufacturing system 10 to function as describedherein. For example, and without limitation, in one alternativeembodiment, rows N are arranged such that each succeeding row is offsetby one-half of a width of a respective vacuum valve 38 from the previousrow.

With reference to FIGS. 2 and 4, in the exemplary embodiment, vacuumsource 32 is coupled in fluid communication with vacuum manifold 36, andin turn, each vacuum valve 38. A first subset 66 of the plurality ofvacuum valves 38 is actuated by controller 18 to selectively draw apartial vacuum through a respective vacuum valve 38 of the first subset66 of vacuum valves 38, thereby generating airflow through the screen 40and the respective vacuum valve 38. With dispenser assembly 34positioned in first material supply source 54, a first portion of firstmaterial particles 26 is entrained in the airflow and is trapped orengaged against screen 40 at each respective vacuum valve 38 of firstsubset 66 of vacuum valves 38. In addition, a second subset 68 of theplurality of vacuum valves 38 is actuated by controller 18 toselectively draw a partial vacuum through a respective vacuum valve 38of the second subset 68 of vacuum valves 38, thereby generating airflowthrough the screen 40 and the respective vacuum valve 38. With dispenserassembly 34 positioned in second material supply source 56, a secondportion of second material particles 28 is entrained in the airflow andis trapped or engaged against screen 40 at each respective vacuum valve38 of second subset 68 of vacuum valves 38. Optionally, in oneembodiment, a third subset 69 of the plurality of vacuum valves 38 isactuated by controller 18 to selectively draw a partial vacuum through arespective vacuum valve 38 of the third subset 69, thereby generating anairflow through the screen 40 and the respective vacuum valve 38. Withdispenser assembly 34 positioned in sacrificial material supply source58, a third portion of sacrificial material particles 60 is entrained inthe airflow and is trapped or engaged against screen 40 at eachrespective vacuum valve 38 of the third subset 69 of vacuum valves 38.

FIG. 5 is a block diagram of controller 18 for use with additivemanufacturing system 10 (shown in FIG. 1). In the exemplary embodiment,controller 18 is coupled to energy source 12, material delivery system24, and mounting system 50. Controller 18 includes a memory device 70and processor 72 coupled to memory device 70. In some embodiments,processor 72 includes one or more processing units, such as, withoutlimitation, a multi-core configuration. In the exemplary embodiment,processor 72 includes a field programmable gate array (FPGA).Alternatively, processor 72 is any type of processor that permitscontroller 18 to operate as described herein. In some embodiments,executable instructions are stored in memory device 70. Controller 18 isconfigurable to perform one or more operations described herein byprogramming processor 72. For example, processor 72 is programmed byencoding an operation as one or more executable instructions andproviding the executable instructions in memory device 70. In theexemplary embodiment, memory device 70 is one or more devices thatenable storage and retrieval of information such as executableinstructions or other data. In some embodiments, memory device 70includes one or more computer readable media, such as, withoutlimitation, random access memory (RAM), dynamic RAM, static RAM, asolid-state disk, a hard disk, read-only memory (ROM), erasableprogrammable ROM, electrically erasable programmable ROM, ornon-volatile RAM memory. The above memory types are exemplary only, andare thus not limiting as to the types of memory usable for storage of acomputer program.

In some embodiments, memory device 70 stores build parameters 31including, without limitation, real-time and historical build parametervalues, or any other type of data. Build parameters 31 include, forexample, and without limitation, the power output, the vector scanningspeed, the raster power output, the raster scanning speed, the rastertool path, and the contour power output of energy source 12. Inalternative embodiments, memory device 70 stores any data that enableadditive manufacturing system 10 to operate as described herein. In someembodiments, processor 72 removes or “purges” data from memory device 70based on the age of the data. For example, processor 72 overwritespreviously recorded and stored data associated with a subsequent time orevent. In addition, or alternatively, processor 72 removes data thatexceeds a predetermined time interval. In addition, memory device 70includes, without limitation, sufficient data, algorithms, and commandsto facilitate monitoring and measuring of build parameters 31 and thegeometric conditions of the component fabricated by additivemanufacturing system 10.

In some embodiments, controller 18 includes a presentation interface 74coupled to processor 72. Presentation interface 74 presents information,such as images, to a user 76. In one embodiment, presentation interface74 includes a display adapter (not shown) coupled to a display device(not shown), such as a cathode ray tube (CRT), a liquid crystal display(LCD), an organic LED (OLED) display, or an “electronic ink” display. Insome embodiments, presentation interface 74 includes one or more displaydevices. In addition, or alternatively, presentation interface 74includes an audio output device (not shown), for example, withoutlimitation, an audio adapter or a speaker (not shown).

In some embodiments, controller 18 includes a user input interface 78.In the exemplary embodiment, user input interface 78 is coupled toprocessor 72 and receives input from the user. In some embodiments, userinput interface 78 includes, for example, without limitation, akeyboard, a pointing device, a mouse, a stylus, a touch sensitive panel,such as, without limitation, a touch pad or a touch screen, and/or anaudio input interface, such as, without limitation, a microphone. Infurther embodiments, a single component, such as a touch screen,functions as both a display device of presentation interface 74 and userinput interface 78.

In the exemplary embodiment, a communication interface 80 is coupled toprocessor 72 and is coupled in communication with one or more otherdevices, such as material delivery system 24, and performs input andoutput operations with respect to such devices while performing as aninput channel. For example, in some embodiments, communication interface80 includes, without limitation, a wired network adapter, a wirelessnetwork adapter, a mobile telecommunications adapter, a serialcommunication adapter, or a parallel communication adapter.Communication interface 80 receives a data signal from or transmits adata signal to one or more remote devices.

Presentation interface 74 and communication interface 80 are bothcapable of providing information for use with the methods describedherein, such as, providing information to user 76 and/or processor 72.Accordingly, presentation interface 74 and communication interface 80are referred to as output devices. Similarly, user input interface 78and communication interface 80 are capable of receiving information foruse with the methods described herein and are referred to as inputdevices.

FIG. 6 is a flow chart of a method 110 that may be implemented tofabricate component 30 using additive manufacturing system 10 (shown inFIG. 1). With reference to FIGS. 1-5, in the exemplary embodiment,controller 18 translates 112 material delivery system 24 to firstmaterial supply source 54. As described herein, first material supplysource 54 includes a quantity of first material particles 26. Materialdelivery system 24 includes the plurality of vacuum valves 38 and airpermeable screen 40. Controller 18 actuates or opens 114 first subset 66of the plurality of vacuum valves 38 to generate airflow through firstsubset 66 of vacuum valves 38 and air permeable screen 40 to entrain afirst portion of first material particles 26 and engage the firstportion of first material particles 26 against air permeable screen 40.The first portion of the first material particles 26 is deposited 116onto build platform 22.

Furthermore, controller 18 translates 118 material delivery system 24 tosecond material supply source 56. As described herein, second materialsupply source 56 includes a quantity of second material particles 28.Controller 18 actuates or opens 120 second subset 68 of the plurality ofvacuum valves 38 to generate the airflow through second subset 68 ofvacuum valves 38 and air permeable screen 40 to entrain a second portionof second material particles 28 and engage the second portion of secondmaterial particles 28 against air permeable screen 40. The secondportion of the second material particles 28 is deposited 122 onto buildplatform 22. In addition or alternatively, depositing 116 the firstportion of first material particles 26 onto build platform 22 occurssimultaneously with the depositing 122 of the second portion of secondmaterial particles 28 onto build platform 22. A melt pool is generated124 in at least one of a portion of the first portion of first materialparticles 26 or the second portion of second material particles 28 withenergy source 12 to facilitate fabricating component 30. Additionally,method 110 may also include vibrating build platform 22 and screedingfirst material particles 26 or second material particles 28 between thesteps of depositing 122 and generating 124.

In an alternative embodiment of method 110, controller 18 furthertranslates material delivery system 24 to a sacrificial material supplysource 58 having a plurality of sacrificial material particles 60.Controller 18 actuates or opens a third subset 69 of vacuum valves 38 ofthe plurality of vacuum valves 38 to generate the airflow through thirdsubset 69 of vacuum valves 38 and air permeable screen 40. The airflowentrains a third portion of sacrificial material particles 60 andengages the third portion of sacrificial material particles 60 againstair permeable screen 40. In such an embodiment, third subset 69 ofvacuum valves 38 is different from first subset 66 of vacuum valves 38and second subset 68 of vacuum valves 38. The third portion ofsacrificial material particles 60 is deposited onto build platform 22.

In the exemplary embodiment, controller 18 deposits 116, 122 firstmaterial particles 26 and second material particles 28 onto buildplatform 22 by closing first subset 66 and second subset 68 of vacuumvalves 38. Closing of vacuum valves 38 facilitates preventing theairflow through air permeable screen 40 and first subset 66 and secondsubset 68 of vacuum valves 38. When the airflow stops flowing throughair permeable screen 40 and first subset 66 and second subset 68 ofvacuum valves 38, first material particles 26 and second materialparticles 28 disengage from air permeable screen 40.

The above described systems and methods relate to additive manufacturingsystems, such as Direct Metal Laser Melting (DMLM) systems. Theembodiments described herein include a material delivery system thatretrieves and deposits a plurality of first material particles and aplurality of second material particles onto a build platform. Thematerial delivery system includes an array of vacuum valves that areindividually controllable to facilitate retrieving select portions offirst and second material particles. In further embodiments, asacrificial material is retrieved and deposited onto the build platformbetween the first and second material particles to facilitate providingsupport to the component being fabricated. Accordingly, the describedembodiments allow components to be fabricated having predetermined,localized material properties. For example, and without limitation,different material particles are included within the same componentlayer during a build of the component to facilitate localization ofmaterial properties within the component.

An exemplary technical effect of the methods and systems describedherein includes at least one of: (a) fabricating components havingpredetermined, localized material properties; (b) reducing time andresources required fabricate components; (c) fabricating componentsincluding different material particles within the same build layer; and(d) providing a material delivery system for simultaneously depositingat least two different material particles onto a build platform.

Exemplary embodiments of additive manufacturing systems including avacuum material delivery system are described above in detail. Thesystems and methods described herein are not limited to the specificembodiments described, but rather, components of systems and/or steps ofthe methods may be utilized independently and separately from othercomponents and/or steps described herein. For example, the methods mayalso be used in combination with other laser fabrication systemsmagnetic bearing systems and methods, and are not limited to practicewith only the systems and methods, as is described herein. Rather, theexemplary embodiments can be implemented and utilized in connection withmany additive manufacturing system applications.

Although specific features of various embodiments of the disclosure maybe shown in some drawings and not in others, this is for convenienceonly. In accordance with the principles of the disclosure, any featureof a drawing may be referenced and/or claimed in combination with anyfeature of any other drawing.

Some embodiments involve the use of one or more electronic or computingdevices. Such devices typically include a processor, processing device,or controller, such as a general purpose central processing unit (CPU),a graphics processing unit (GPU), a microcontroller, a reducedinstruction set computer (RISC) processor, an application specificintegrated circuit (ASIC), a programmable logic circuit (PLC), a fieldprogrammable gate array (FPGA), a digital signal processing (DSP)device, and/or any other circuit or processing device capable ofexecuting the functions described herein. The methods described hereinmay be encoded as executable instructions embodied in a computerreadable medium, including, without limitation, a storage device and/ora memory device. Such instructions, when executed by a processingdevice, cause the processing device to perform at least a portion of themethods described herein. The above examples are exemplary only, andthus are not intended to limit in any way the definition and/or meaningof the term processor and processing device.

This written description uses examples to disclose the embodiments,including the best mode, and also to enable any person skilled in theart to practice the embodiments, including making and using any devicesor systems and performing any incorporated methods. The patentable scopeof the disclosure is defined by the claims, and may include otherexamples that occur to those skilled in the art. Such other examples areintended to be within the scope of the claims if they have structuralelements that do not differ from the literal language of the claims, orif they include equivalent structural elements with insubstantialdifferences from the literal language of the claims.

What is claimed is:
 1. A method of fabricating a component using anadditive manufacturing system, said method comprising: entraining afirst portion of first material particles in an airflow generated by avacuum source and engaging the first portion of the first materialparticles against an air permeable screen; depositing the first portionof the first material particles onto a build platform; entraining asecond portion of second material particles in the airflow and engagingthe second portion of the second material particles against the airpermeable screen; depositing the second portion of the second materialparticles onto the build platform; and transferring heat to at least aportion of at least one of the first portion of the first materialparticles or the second portion of the second material particles with anenergy source to facilitate consolidating the first portion of the firstmaterial particles and the second portion of the second materialparticles to fabricate the component.
 2. The method in accordance withclaim 1, wherein entraining a first portion of first material particlesin an airflow comprises opening a first subset of vacuum valves of aplurality of vacuum valves to generate the airflow through the firstsubset of vacuum valves and the air permeable screen.
 3. The method inaccordance with claim 2, wherein entraining a second portion of secondmaterial particles in the airflow comprises opening a second subset ofvacuum valves of the plurality of vacuum valves to generate the airflowthrough the second subset of vacuum valves and the air permeable screen,wherein the second subset of vacuum valves is different from the firstsubset of vacuum valves.
 4. The method in accordance with claim 1further comprising translating a material delivery system to a firstmaterial supply source including the first material particles, thematerial delivery system including a plurality of vacuum valves and theair permeable screen.
 5. The method in accordance with claim 4 furthercomprising translating the material delivery system to a second materialsupply source including the second material particles.
 6. The method inaccordance with claim 1, wherein depositing the first portion of thefirst material particles onto a build platform occurs simultaneouslywith the depositing the second portion of the second material particlesonto the build platform.
 7. The method in accordance with claim 1further comprising translating the material delivery system to asacrificial material supply source having a plurality of sacrificialmaterial particles.
 8. The method in accordance with claim 7 furthercomprising opening a third subset of vacuum valves of the plurality ofvacuum valves to generate an airflow through the third subset of vacuumvalves and the air permeable screen, the airflow entraining a thirdportion of the sacrificial material particles and engaging the thirdportion of the sacrificial material particles against the air permeablescreen, wherein the third subset of vacuum valves is different from thefirst subset of vacuum valves and the second subset of vacuum valves. 9.The method in accordance with claim 8 further comprising depositing thethird portion of the sacrificial material particles onto the buildplatform.
 10. The method in accordance with claim 9, wherein depositingthe third portion of the sacrificial material particles onto the buildplatform comprises closing the third subset of vacuum valves to preventthe airflow through the third subset of vacuum valves and the airpermeable screen such that the third portion of the sacrificial materialparticles disengage from the air permeable screen.
 11. The method inaccordance with claim 1, wherein depositing the first portion of thefirst material particles onto the build platform comprises closing thefirst subset of vacuum valves to prevent the airflow through the firstsubset of vacuum valves and the air permeable screen such that the firstportion of the first material particles disengage from the air permeablescreen.
 12. The method in accordance with claim 1, wherein depositingthe second portion of the second material particles onto the buildplatform comprises closing the second subset of vacuum valves to preventthe airflow through the second subset of vacuum valves and the airpermeable screen such that the second portion of the second materialparticles disengage from the air permeable screen.
 13. The method inaccordance with claim 1, wherein transferring heat comprisestransferring heat with the energy source based on one or more of thefollowing: a power output, a vector scanning speed, a raster poweroutput, a raster scanning speed, a raster tool path, and a contour poweroutput of the energy source.
 14. An additive manufacturing system forfabricating a component, said additive manufacturing system comprising:an energy source; a material delivery system comprising: a dispenserassembly comprising a plurality of vacuum valves and an air permeablescreen; and a vacuum source coupled in fluid communication with saidplurality of vacuum valves; and a controller configured to: open a firstsubset of vacuum valves of said plurality of vacuum valves to generatean airflow through said first subset of vacuum valves and said airpermeable screen to retrieve a plurality of first material particles;open a second subset of vacuum valves of said plurality of vacuum valvesto generate an airflow through said second subset of vacuum valves andsaid air permeable screen to retrieve a plurality of second materialparticles; depositing on a build platform said plurality of firstmaterial particles and said plurality of second material particles; andactuate said energy source to transfer heat to at least one of saidplurality of first material particles and said plurality of secondmaterial particles based on a build parameter to facilitateconsolidating said plurality of first material particles and saidplurality of second material particles to fabricate said component. 15.The system in accordance with claim 14 further comprising a firstmaterial supply source comprising said plurality of first materialparticles and a second material supply source comprising said pluralityof second material particles.
 16. The system in accordance with claim 15further comprising a mounting system coupled to said material deliverysystem, said controller further configured to: translate said materialdelivery system to said first material supply source to retrieve saidplurality of first material particles; and translate said materialdelivery system to said second material supply source to retrieve saidplurality of second material particles.
 17. The system in accordancewith claim 14, wherein said dispenser assembly further comprises avacuum manifold coupled to said plurality of vacuum valves, said vacuumsource coupled in fluid communication with said vacuum manifold.
 18. Thesystem in accordance with claim 14 further comprising a build platformconfigured to hold said plurality of first material particles and saidplurality of second material particles, wherein said controller isfurther configured to deposit said plurality of first material particlesand said plurality of second material particles onto said buildplatform.
 19. The system in accordance with claim 18 further comprisinga sacrificial material supply source comprising said plurality ofsacrificial material particles, said controller further configured to:open a third subset of vacuum valves of said plurality of vacuum valvesto generate an airflow through said third subset of vacuum valves andsaid air permeable screen to retrieve said plurality of sacrificialmaterial particles; and deposit said plurality of sacrificial materialparticles onto said build platform.
 20. The system in accordance withclaim 14, wherein the build parameter includes one or more of thefollowing: a power output, a vector scanning speed, a raster poweroutput, a raster scanning speed, a raster tool path, and a contour poweroutput of said energy source.
 21. A material delivery system for anadditive manufacturing system, said material delivery system comprising:a dispenser assembly comprising a plurality of vacuum valves and an airpermeable screen; a vacuum source coupled in fluid communication to saidplurality of vacuum valves; and a mounting system coupled to saiddispenser assembly.
 22. The system in accordance with claim 21, whereinsaid mounting system translates said dispenser assembly materialdelivery system between one or more material supply sources and a buildplatform of the additive manufacturing system.
 23. The system inaccordance with claim 21, wherein said dispenser assembly furthercomprises a vacuum manifold coupled to said plurality of vacuum valves,said vacuum source coupled in fluid communication to said vacuummanifold.
 24. The system in accordance with claim 21, wherein saidplurality of vacuum valves are arranged in an M×N array, wherein Mcorresponds to a number of columns in the array, and wherein Ncorresponds to a number of rows in the array.
 25. The system inaccordance with claim 21, wherein said M×N array has a size and shapethat substantially corresponds to a size and shape of a build platformof the additive manufacturing system.